WIP Remote Desktop Portal

[ids1024]

Requires pop-os/cosmic-comp#465.

This is the minimal require for a client that uses the portal to get a libei fd.

I guess we need a secure mechanism to get a libei fd for a specific device bitflag field, and this should implement the legacy non-ei methods by lazily connecting to an ei socket if they are used? This will also need a dialog.

[olafkfreund]

Hi @ids1024, I've built on the groundwork you started here and implemented a more complete RemoteDesktop portal in PR #271.

My implementation adds:

• Consent dialog UI with device type chips (keyboard/pointer/touchscreen icons) and output/window selection tabs
• Full session lifecycle management with proper cleanup
• EIS socket pair creation and forwarding to the compositor via D-Bus (AcceptEisSocket)
• Security hardening: consent dialog always shown (never skipped via restore data), device type validation, per-session socket isolation
• Reuse of existing ScreenCast infrastructure (ScreencastThread, StreamProps)
• i18n strings for the dialog

I followed the naming convention from your PR (remote_desktop.rs) and used your reis crate for the EIS protocol support.

On the compositor side, I have a fork at https://github.com/olafkfreund/cosmic-comp-rdp that provides the AcceptEisSocket D-Bus method, and an RDP server at https://github.com/olafkfreund/cosmic-rdp-server that uses the portal end-to-end.

Happy to collaborate on getting this upstream — let me know if you'd like me to adjust anything in #271 to align with your plans for the compositor integration or if there's a preferred approach for the EIS socket handshake.